Files
Varaverk/Plugin/unraid/api/config.php
T
Gmer4Lfe 987313e7dc Document the PHP api layer and fix what documenting it exposed
Writing down what each endpoint actually guarantees made the places it
didn't obvious — shell arguments reaching a crontab or a bash -c
unescaped, master.conf written without tmp+rename, and conf edits that
could be saved without ever being parsed.
2026-08-02 10:11:39 -04:00

97 lines
4.8 KiB
PHP

<?php
// ═══════════════════════════════════════════════════════════════════════════════════════════════
// PURPOSE
// Conf save endpoint. Writes the full text of one configuration file back to
// Configurations/, for the settings tab's raw editor.
//
// OPERATIONAL MODEL
// Whole-file replacement, not a patch. The editor sends back everything it was given, so a
// save is a straight overwrite. There is no merge, no per-key update, and no attempt to
// reconcile with a concurrent edit — last writer wins, which is correct for a single-admin
// plugin and far more predictable than a partial merge of a bash file.
//
// DESIGN PRINCIPLES
// Which files exist is decided by the host, never by the request.
// vv_get_conf_files() returns the allowlist for this host — master.conf plus its own
// host conf on HOST1, its own conf alone elsewhere. The filename is checked for exact
// membership in that list. This is what keeps sparse checkout honest: HOST2 cannot be
// asked to write host1.conf, because host1.conf is not in its list.
//
// Raw is the point.
// The structured editor is confform.php. This endpoint exists for the cases that one
// cannot express — new keys, comments, array literals, bulk edits — so it deliberately
// does not parse, reformat, or normalise what it is given.
//
// OPERATIONAL SAFEGUARDS
// POST only. Refused before the allowlist is even consulted, so a link or a prefetch can
// never reach the write path.
//
// Exact allowlist membership, not a pattern.
// in_array() against vv_get_conf_files() — not a regex, not a prefix test, not
// basename(). A filename that is not literally one of the permitted strings is rejected,
// which makes traversal and absolute paths unreachable rather than merely filtered.
//
// The content is syntax-checked before it can replace a working file.
// Conf files are sourced by every script in the system. A stray quote saved here would
// break load_config.sh, and with it every orchestrator, watchdog and fallback path — on
// a machine whose whole purpose is running unattended. `bash -n` on a private temp copy
// is the difference between a rejected save and a silent, total outage, so a file that
// does not parse is refused and the previous version is left untouched.
//
// The temp copy is created with tempnam() and always removed.
// The candidate is never written next to the real conf and never under a predictable
// name, so a failed validation cannot leave a stray file for a script to source.
//
// The real write is atomic.
// vv_write_conf_raw() writes .vv.tmp and rename()s, so a script sourcing the conf
// during the save reads either the old file or the new one, never a half-written one.
//
// REQUEST
// POST file=<allowed conf name> content=<full file text>
//
// RESPONSE
// {"ok":true,"error":null}
// {"ok":false,"error":"POST only"|"File not permitted"|"Syntax error: …"|"Failed to write file"}
//
// DEPENDS ON
// include/config.php vv_get_conf_files(), vv_write_conf_raw(), CONF_DIR
// ═══════════════════════════════════════════════════════════════════════════════════════════════
header('Content-Type: application/json');
require_once dirname(__DIR__) . '/include/config.php';
if ($_SERVER['REQUEST_METHOD'] !== 'POST') {
echo json_encode(['ok' => false, 'error' => 'POST only']);
exit;
}
$file = trim($_POST['file'] ?? '');
$content = $_POST['content'] ?? '';
// Must be an allowed file for this host
$allowed = vv_get_conf_files();
if (!$file || !in_array($file, $allowed)) {
echo json_encode(['ok' => false, 'error' => 'File not permitted']);
exit;
}
// Every script sources these. A syntax error here takes the whole system down, so the
// candidate is parsed before it is allowed to replace a working file.
$check = tempnam(sys_get_temp_dir(), 'vvconf');
if ($check !== false) {
file_put_contents($check, $content);
$out = []; $rc = 0;
exec('bash -n ' . escapeshellarg($check) . ' 2>&1', $out, $rc);
@unlink($check);
if ($rc !== 0) {
$msg = implode(' ', array_filter(array_map('trim', $out)));
echo json_encode([
'ok' => false,
'error' => 'Syntax error: ' . str_replace($check, $file, $msg ?: 'conf does not parse'),
]);
exit;
}
}
$ok = vv_write_conf_raw($file, $content);
echo json_encode(['ok' => $ok, 'error' => $ok ? null : 'Failed to write file']);